Coal auger



Mx HRI..

CUAL AUSER.

APPLICATION FILED IIIAYzB. 191s.

Patented Oct. 8, 1918.

lieyersdale,

MILTON FIEL, QF MEYEBSDALE, PENNSYLVANIA..

GOAL-Aucun.

To all whom t may concern.'

Be it known that. Il` MILTON FIRL, a citizen-of the United States, and resident of lcounty of' Somerset, State of Pennsylvania. have invented certain new and useful Improvements in Coal4Augers, 'of Which the following is a specification.

This invention relates to certain improvements in and relating to coal angers or drills and the like, and the objectsand nature of the invention will be readily understood by those skilled 'in the art in the light of the following explanation of the accomanying drawing illustrating what I now Believe to be the preferred mechanical expression or embodiment of my invention from -among other forms and constructions within the spirit and scope thereof.

An object of the invention is to produce an auger or drill of the spirally twisted type, peculiarly adapted for boring holes for blast-ing purposes in coal mining operations and the like, provided with a cutting endimbodying improved renewable cutting bits whereby the stem an'd twisted body of .the bit can be composed of' iron or other comparatively inexpensive material which will not break as readily as steel under lateral or bending strain, and whereby reduction in the length of the twisted body by wear will be avoided and only a comparatively small -quantity of expensive steel will be needed for the 'bits o'r cutters which can be readily removed for sharpening and when unduly worn be renewed at comparatively small expense.

A' further object of the invention i-s to rovide a coal auger or the like, with an improved cutting end or point embodying renewable removable cutting bits ot' peculiar torn-lation and designed and arranged tol break up the core formed in the boring operation and joined to the body ot' the auger lin a novel manner to withstand -the strains and stresses to which said bits are subjected in operation. l

With these and other objects in view, my invention consists in cert-ain novel features in construction and in arrangements and combinations as more fully and particularly pointed' out. hereinafter.

Referring to the accompanying drawings z- Figure 1, is a side elevation sbowinga p0rtion of a spil-ally twisted auger stem or body Speeiiexition of Letters Patent.

Patented Oct 8, 1918.

Application led May 2 8, 192,8. Serial No. 237,107.

equipped with a cutting point or end embodying my invention.

Fig. 2, is also a. side elevation from a point of vie-w at right angles to that'from which Fig. 1, .is takenf-A Fig. 3', is an d view of the cutting end of the auger.

Fig. si, is adetail view.

In the drawings, I show a portion of the spiral or twisted body or stem l, of a coal or like auger. In common practice, such angers are usually composed throughoutof steel and the ends thereof are split and formed into cutting points integral with the spiral body. iVhen such points become unduly Worn it is a difficult and co1nparativelv expensive operation to resplit the end of tlie body and reform the points, without -l considering the constant' reduc-tion in the length of the auger and the consequent waste as the auger must be discarded when reduced to a certain length.

Furthermore, the nature of the steel is such, that the long angers sometimes break or snap ofi' when subjected to undue lateral pressure and strain during operation as is apt to occur when the angers are used in body or breast braces and rotated by hand.

I prefer to make the spiral or twist body 1 of iron' or other comparatively inexpensive metal that can {iex or bend under the conditions mentioned. wit-hout fracturing or breaking.

My invention also contemplates the formation of the end ot' the spiral orrtwisted bodyl, to provide a pair of similar for wardly diverging projecting stubs, fingers or bit bases i2, integral with the body. These stubs diverge with respect to each other to form an angle of approximately ninety degrees and each stub is approximately equal to one halt' the width ot the bar forming the spiral. while the end of the bar forming said fingers gradually increases in thickness toward the stubs to render said stubs of in# creased thickness.

The two stubs are diametrically opposite each other with respect to the longitudinal axis of the spiral body vof the auger and are that the exterior circle or diameterbf thel end of the body formed by said stubs will be approximatelythe saine as lthe exterior diameter of the body behind said end and the edges 3 will engage or follow'the wall of the bore or hole being eut in the same manner as edges 4.

The side faces 5, 6, of the stubs form con tinuations of the corresponding side faces of the spiral body, and the front or advancing side faces 5, of the stubs are comparatively fla-t and meet the inner faces 8 of the stubs to form inner front longitudinal eut-ting edges 7, to aid in breaking down the core as hereinafter explained.

The outer ends ofthe stubs are cut off or otherwise formed to present oblique faces or shoulders to receive and interlock with the heels of the bits as hereinafter set forth.

Each stub is provided with a bit or cut-A ter 9 shaped to 4form a longitudinal continuation of its stub and of its outer, inner and side faces.

The two cutters or bits are similar and interchangeable, and each is preferably of the same thickness throughout its length 'so that its front and rea-r'faces 10, 11, are approximately parallel, but each bit reduces or tapers forwardly in width to rovide the front cutting orchisel edge 12. he edge 12 is straight and extends from face 10 to face 11 but is arranged obliquely or at an inclination to form the front cutting point 13, and cause the edgeto cut with a shearing action With the maximum diameter of the cut at the rear points or ends 14 of said edges. f

The bits are curved longitudinally in longitudinal continuation of the stubs and the outer edges or faces 15 of the bits form continuations of the edges 3 of the stubs and edges 4 ofthe spiral body and are longi tudinally curved '1n approximate accordance therewith.

The advancing or front side faces 10 of the bits squarely meet the inner edge faces of the bits to form longitudinal 'inner or advancing cutting edges 16 in continuation of the cutting edges 7 of the stubs and cooperating therewith to cut and break down the core left within the circular path of operation of points 13 and edges 12.

The bits are removably secured to and suitably anchored in the stubs to Awithstand the tremendous pressure and strain to which they are subjected in action. In the particular example illustrated.' each stub is `formed with an intermediate longitudinal slot or mortise 17, arranged about midway between and parallel with its inner and outer faces and the end of the stub at the inner side of the slot forms a square or angular tenon 18 and shoulder 19 while the end of the stub at the outer side of the slot forms a tapered or wedgeshaped tenonl 20.

The heel of each bit is correspondmgiy formed to provide a tenon 21, to snugly tit niortise 17 and a tapered or wedge-shaped depression or mortise 22 to receive-tenon-20, and an angular or square mortise 23 to receive tenori 18 and an edge 24 to abut shoulder 19.

It will be noted that the transverse end edges of the heel of the bit 'and of the stub are parallel with the length of the cutting edge 12 and :that the flat side faces of the tenon 21 are parallel with said edge and also that the end faces of the various tenons squarely fit and abut against the floorsof 4the various mortises forming abutting shoulders parallel with the edge 12 and thereby tending to directly receive the thrust and pressure of the bits in action and maintain the same in-rigid continuation of the stubs. i The'wedge like mortise and tenon 22, 2 0,

are arranged at the' outer or rear edge por-4 .tion of the bitV so that the outward pressure or strain on the bit during action will tendbut to tighten the heelof the bit 'in the stub.

Various means-can be provided to lock v the bits in the stubs although I show locking pins 28 removably fitting registering perforations l 26, 27, extending transversely through the lstubs and tenons 21. These pins are arranged transversely with respectA to the' cutting edges 12and -are preferably so to be driven inwardly'with' arranged as their heads or large ends flush with the'outer faces. Thus should a pin become loose and start to work out while the au er is boring, the operator would immediate y 'become advised of such fact by reason of the engagement of the head of the pin` with the vwall of the hole or bore. lVhen the pins are thus arranged with their large ends at the outer surfaces of the stubs, the pins are removed by applying extracting means at their inner ends at the inner edges or faces of the stubs..

These bits can be readily sharpened with out removal by filing or grinding their inner lfaces. When the bits have been unduly shortened by repeated sharpening, thcycan be easily removed and new and perfect bits can be applied, at comparatively slight ex'- pense. v

It is evidentthat various changes,'modi ications and departures might be resorted to without departing from the spirit and scope of my invention and hence -I do not wish to limit myself to the exact disclosures hereof.

What I claim iszl. In coal angers and the like, a spirallytwisted body having a cutting end composed of a pair of similar forwardly diverging cutters; said cutters consisting of a pair of diverging stubs integral with the body and rasatura'v :of-short interchangeable bits forming longitudinal.continuations of said stubs, the

"stubs and bits being longitudinally mortised 1` and tenoned and interlocking for both transverse and longitudinal removal and application of either bit, the heelsof the bits and ends of the'stubsprovidin transverse squarely abutting shoulders, t e mortised and tenoned portions of a bit and stub being 101v the-inner andouter edges ofthe cutter and providing flat faces of the. same width asl andi approximately parallel with said edges' nally axis and having a cutting end consistpoints exceeding the extreme diameter of.

arranged approximately midway between ofthecutter, said inner and outer edges of thebit meeting atthe outer end to formthe samewith a straight cutting edge, and means forbindependently locking. each bit to its stu u 2. In coal augers and the like, an elongated body rotatable around its ,longitudiing of a pair of forwardly diverging cutters composed of diverging stubs integral with the body and short bits forming longitudinal continuations of the stubsl respectively, each vcutter having a straight. front chisel cutting edge forming an inner front cutting point andan outer rearward point,

said edges being inclined rearwardly and outwardly from said front points to said.

rear points, the distance between said rear the body, veach lcutter having a front lpngitudinal corner edgey meeting lits front point and extending rearwardly and -vinwardly therefrom 'toward said longitudinal axial line, the heels of the bits removably interlocking with the stubs, and means for locking the bits to the stubs, .each stub presenting transverse oblique shoulders and each bit having transverse' shoulders approxih mately parallel with itsfchisel edge and squarely abutting said stu-b shoulders.

3. A coal auger comprising aV spirally4 twisted body having a pair of end stubs of increased thickness with respect thereto and .integr-al therewith and diverging forwardly to form an intervening angle of approximately ninety degrees, the outer longitudinal edges of said stubs forming curved longitudinal continuatons of the spiral longitudinal edges of the body, the front and rear side faces of the stubs forming longif tudinal continuations of thecorrespondin spiral side faces of the body, and a pair o short interchangeable' bits forming longitudinal forward continuat'ons ofthe stubs and `removably interlocked therewith and secured thereto, the inner and outer edges of each bit forming longitudinal continuations of the inner and outer edges of its stub and converging forwardly to a front cuttin edge, the front and lrear faces of each blt forming longitudinal continuations of the corresponding faces of its stub, the' front inner longitudinal corners of the bits and- V stubs forming cutting edges to vbreak down the core, y

4. In coal angers and the like', a body'of the spirally twisted type provided with a pair of short forwardly diverging removable cutting bits having their outer lon tudinal edges curved in continuation of t e spirally curved longitudinaledges of the body, each bit having a heel longitudinally interlocking with the end'of the body, and removable bit locking means extending inwardly through said edges and the inter- -locking portions of the bits and body, said means being removable outwardly whereby the outer ends of said means will engage the wall of the hole, should said means accidentally work loose while the auger is in action.

5. In coal augers and the like, a spirallytwisted body of increased thickness at its cutting .end and provided with a pair of Vindependent forwardly diverging inter- MILTON FIRL. 

